The primary aim of this feasibility study is to determine if a Cardiac Arrhythmia Trans telephonic EKG monitoring system (CAT) can be used to detect asymptomatic or "silent" arrhythmias in patients greater than or equal to 65 years of age with a history of hypertension (HTN) and heart failure (HF) and characterize their onset, frequency, and duration. The secondary aim is to examine the association between silent arrhythmias and quality of life (QoL). Atrial fibrillation (AF) is the most common arrhythmia and its prevalence increases with age, HTN, and HF. It also has a profound impact on QoL. Whether silent or symptomatic, AF can result in stroke. Detection of silent arrhythmias, especially silent AF, could prompt the initiation of anticoagulation that would decrease the occurrence of stroke, which is the third leading cause of death in the US. As treatment for HTN and HF continue to improve, combined with increased life expectancy, early arrhythmia identification strategies are urgently needed to predict who is at the highest risk for silent arrhythmias. Standard methods for detecting AF include 12-lead EKGs, 24-hour Holter recorders (HM) and non-auto-triggered memory loop recorders (MLR). MLRs are unable to automatically detect and capture silent arrhythmias since they require patient activation during symptoms. Auto-triggered MLRs (AT-MLR) have recently become available which automatically record arrhythmias, with or without associated symptoms, and the stored EKG data can then be transmitted trans telephonically (via phone) to a central monitoring station. A recently completed retrospective analysis has shown that AT-MLRs produced a higher yield of diagnostic events and an earlier time to diagnosis of silent arrhythmias as compared to HM or MLR. This study proposes a single-center, prospective consecutive series of 100 patients using a 14-day CAT monitoring period. At baseline and 6 months, cardiac clinical characteristics and risk factors will be collected from patients via physical exam and chart review, and the SF-36v2(TM) will be administered to determine if differences exist in perceived QoL in patients with silent AF. Information regarding AF frequency and duration will be quantified using the University of Toronto Atrial Fibrillation Scale (AFSS). Spearman's correlation will be used to assess the association between AF and changes in SF-36v2(TM) QoL scores between baseline and 6 months. The relationship between AF, demographic, and clinical characteristics will be determined using logistic regression analysis. All significant univariate variables will be entered into a multivariate logistic regression model. The results of this feasibility study could potentially justify development of a new screening mechanism for silent AF. If this study proves successful, a larger trial will be proposed to explore specific clinical variables, EKG characteristics, and treatment strategies to improve clinical care and QoL. [unreadable] [unreadable] [unreadable]